Autoantibodies in systemic sclerosis overlap syndrome and their correlation with organ damage and survival.

Background: Systemic sclerosis (SSc) often overlaps with other autoimmune diseases. More complex autoantibody profiles may be observed in SSc overlap syndrome (SSc OS). To determine the clinical significance of autoantibodies in SSc OS and classify the patients more accurately for better disease assessments, we analysed the correlation between serological profiles, organ involvements and outcomes.

Methods: A retrospective cohort study was conducted in Peking University People's Hospital. Chi-square tests and analysis of variance were used to analyse univariate comparisons of clinical symptoms, organ involvement and laboratory indicators. Survival was evaluated using Cox proportional hazards model.

Results: Among 141 cases, anti-Ro-52 was the most common antibody, followed by anti-centromere antibody and anti-Scl-70 antibody. We analysed the correlation between autoantibodies and vital organ damage in SSc OS patients, and compared the differences across four SSc OS subgroups (SSc SLE, SSc RA, SSc PM/DM and SSc SS) to demonstrate the correlation between autoantibodies and clinical characteristics and organ damage. Cox regression analysis showed that scleroderma renal crisis (SRC) (p = .004) and pulmonary arterial hypertension (PH) (p = .010) were independent risk factors for survival.

Conclusions: Autoantibodies are associated with clinical features, organ involvement and prognosis in SSc OS patients. Anti-Scl-70 antibody is associated with interstitial lung disease (ILD) and SRC, while ACA is a protective factor of ILD. SRC and PH are risk factors associated with death.